Modular blocks for rainwater recovery system

ABSTRACT

A modular block, useful for constructing liquid-storage tanks for water-recovery systems, is described. The blocks can support large vertical loadings, may be fabricated from synthetic materials, and can be assembled into a tank-like structure. Because of their small size, light weight and easy portability, custom-sized water-recovery tanks may be readily assembled and installed at competitive costs. The water-recovery tanks may be used to reclaim runoff rainwater from water-impervious surfaces.

CROSS-REFERENCE TO RELATED U.S. APPLICATIONS

The present continuation-in-part application claims priority to U.S.patent application Ser. No. 11/395,989 filed on 31 Mar. 2006, which is acontinuation of U.S. patent application Ser. No. 10/651,570, now issuedU.S. Pat. No. 7,025,076, which claims priority to ProvisionalApplication No. 60/407,162, filed on 30 Aug. 2002.

FIELD OF THE INVENTION

This invention relates to underground liquid-storage tanks or cisterns.In particular, modular blocks are described which can be assembled toform a cavity of an underground storage tank. The tank can be used forreclaiming and recovering rain water.

BACKGROUND

Many urbanized areas in the United States are running out of potablewater, and improvements in water quality are becoming increasinglydifficult and expensive to attain. Most of these environmental problemsare related to the proliferation of impervious (paved or constructed)surfaces. Imperviousness has a double-edged effect: it interrupts thenatural hydrologic cycle, and it contributes to flooding-relatedproblems. Interruption of the hydrologic cycle disconnects rainfall fromreplenishing groundwater supplies, particularly by natural waterinfiltration into soil covered with vegetation. Impervious surfaces alsocontribute to storm-water runoff, flooding problems, in-stream erosion,and increased frequency of Combined Sewer Overflow (CSO) discharges. Fora general treatise on the hydrologic cycle, the interaction of groundwater and surface water, and water management, see Winter et al., GroundWater and Surface Water: A Single Resource, U.S. Geological SurveyCircular 1139, U.S. Government Printing Office, Denver, Colo., 1998, 79pp., the teachings of which are incorporated herein by reference.

Imperviousness is generally associated with growth, and growth isassociated with greater water demand. The consequence is that there isless water stored while more water is demanded. Additionally, eachsummer demand for potable water doubles in many communities as residentsseek to irrigate their lawns, while in urbanized areas a preferredmethod of treating wastewater is through large regional systems thatmove water out of a basin or sub-basins. The result is that demand forpotable water frequently exceeds supply and causes many communities toenforce restrictive water bans during the summer months.

One system used to mitigate the effects of urbanization on waterresources has been disclosed in U.S. Pat. No. 7,025,076. Such a systememploys underground water storage tanks to capture and hold rainwaterrunoff for later use.

SUMMARY

There is a need for low-cost, easily-transportable, readily-installableliquid-storage tanks that are useful for such applications as rainwaterreclamation. To this end, an interconnecting block system, useful forconstructing liquid-storage tanks, is described. In various embodiments,a connectable modular block has a substantially rectangular lowersurface element perforated with holes, and a similar rectangular uppersurface element also perforated with holes. The lower surface and theupper surface are substantially parallel to each other, and connected toeach other with at least one vertical support having multipleperforations. In some embodiments, one or more reinforcing braces attachto the vertical supports to provide greater rigidity to the block, and ablock having upper and lower surfaces measuring about two feet by twofeet can support at least about 1,000 pounds.

In some embodiments, integrated onto the block are male-type andfemale-type fastening mechanisms. These fasteners permit aligned andregistered assembly of multiple blocks, so that a large liquid-storagevolume can be readily formed from smaller, easily-transportable modularblocks. Once assembled, the ensemble can be reinforced with syntheticcord and wrapped with a water-impermeable barrier to form a tanksuitable for underground storage of water for various non-potable uses.

The blocks can be fabricated from a variety of low-cost materials usingany one of several fabrication processes. Materials that may be used toform the blocks include various plastics such as, but not limited to,nylon, vinyl, polyvinylchloride, polycarbonate, acrylic, polyethylene,polyurethane, or polystyrene. The blocks may be formed by extrusion,injection molding, rotational molding, or casting processes known tothose skilled in the art of forming plastics.

A liquid-storage tank formed from multiple interconnected blocks maycontain at least one inlet port and at least one outlet port. In someembodiments, rainwater collection system may be connected to the tank'sinlet port, and a pump may be connected to an outlet port from the tank.The pump may be used to move the stored water for irrigation purposes,washing purposes, ornamental purposes, or other non-potableapplications.

In various embodiments, one or more tanks formed from theinterconnecting blocks may be connected by piping or tubing. In otherembodiments, one or more tanks may further be connected to a dry well,such that collected water in excess of the total tank volume flows intothe dry well for infiltration into groundwater supplies and aquiferrecharge.

In some embodiments, a roofwasher first-flush system may be disposedbetween a roof-water collection system and a tank's inlet. The roofwasher system collects a first runoff water volume, and diverts it awayfrom the storage tank. Accordingly, debris and pollutants that mayaccumulate during non-rainy periods are diverted away from the storagetanks.

The present invention offers the following environmental benefits:increased ground water recharge; decreased runoff volume and peak flowsto storm drains; decreased potential for flooding; improved storm-waterquality; reduced potable water demand; strategic emergency non-potablewater supply; potential to offset the effect of local well withdrawalsby recharging groundwater supply.

When used by a homeowner, the present invention offers the followingbenefits: a supply of non-potable water for lawn care, car washing,plantings etc.; a reduction in municipal water expense by reducing thedependency on municipal water supplies for non-potable uses; a source ofwater during town watering bans and restrictions; knowledge that you arehelping to restore our natural environment.

The foregoing and other aspects, embodiments, and features of thepresent teachings can be more fully understood from the followingdescription in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The skilled artisan will understand that the figures, described herein,are for illustration purposes only. It is to be understood that in someinstances various aspects of the invention may be shown exaggerated orenlarged to facilitate an understanding of the invention. In thedrawings, like reference characters generally refer to like features,functionally similar and/or structurally similar elements throughout thevarious figures. The drawings are not necessarily to scale, emphasisinstead being placed upon illustrating the principles of the teachings.The drawings are not intended to limit the scope of the presentteachings in any way.

FIG. 1A is an elevation view of an embodiment of a modular block usefulfor constructing a liquid-storage tank. The block has substantially flattop surfaces and bottom surfaces.

FIG. 1B is a top-down view of the modular block of FIG. 1A.

FIG. 2A is an elevation view of a liquid-storage tank. The volume of thetank is substantially defined by an assembly of modular blocks. Theblocks are covered or wrapped with a water impermeable barrier. In theillustration, the barrier is portrayed in cut-away view to reveal theblocks inside the tank.

FIG. 2B is a bottom-up view of the tank of FIG. 2A.

FIG. 3 is a schematic illustration of a rainwater recovery systemaccording to one embodiment of the invention. In this embodiment, wateris collected from a building's roof and directed into a storage tank 335formed from multiple blocks.

FIG. 4 is a schematic illustration of a first flush diverter systemaccording to one embodiment of the invention. The first flush of wateris collected in a lower tank 329 until the stopper 325 closes the entryport 324.

FIG. 5A is an elevation view of an embodiment of a modular block usefulfor constructing a liquid-storage tank.

FIG. 5B is a top-down view of the modular block of FIG. 5A.

FIG. 6A is an elevation view of the top element of a modular block, anddepicts and embodiment for registering and interlocking the modularblocks.

FIG. 6B is a schematic illustration of an interlocking system for themodular blocks. A dumbbell-shaped fastener, shown in top view and sideview at left, snaps into receptacles in the top and bottom of the block,as indicated in the diagram on the right.

The features and advantages of the present invention will become moreapparent from the detailed description set forth below when taken inconjunction with the drawings.

DETAILED DESCRIPTION

The present invention is useful for capturing runoff water and storingsome of the water for non-potable uses, such as but not limited to,irrigation, car washing, exterior building washing, walkway cleaning,and ornamental purposes. The present invention can reduce the demand ofpotable water and depletion of valuable potable water supplies for suchnon-potable uses. The present invention can be used to construct one ormore liquid-storage tanks that may be located above ground orunderground, and these tanks can be used to collect and store runoffrainwater.

In overview and referring to FIG. 1A-1B, a modular block 100, useful forconstructing liquid-storage tanks, is depicted in elevation view andtop-down view. The modular block has substantially flat or smooth top110 and bottom 190 surfaces, and these surfaces are joined to verticalmembers 140. In various embodiments, holes 150, 160, and 105 aredistributed throughout the structure. The block may have width, depthand height dimensions represented substantially by W, D, and H. Anynumber of blocks may be joined together to form a skeleton which definesthe cavity or volume of a tank as indicated in FIG. 2A-2B.

The block shown in FIG. 1A-1B may be formed from a variety of materialsusing various forming processes. For example, the material used to makethe block may be any one of the following synthetics: nylon, vinyl,polyvinylchloride, polycarbonate, polystyrene, polyurethane,polyethylene, acrylic, lexan, and other similar plastics. Othermaterials such as fiberglass, cermamics and cement may be used, as wellas aluminum. The block may be comprised of a coated material, such asrubber- or plastic-coated steel. In various embodiments, the block maybe formed by casting, rotational molding, extrusion or injection-moldingprocesses, as well as mechanical assembly.

The enclosed volume V_(e) of a block 100 may be defined substantially byits overall dimensions: V_(e)=W×D×H. The occupancy volume V_(o) of theblock may be defined as the actual volume filled by the block material,and can be found from the following relation:

$\begin{matrix}{V_{o} = \frac{M}{\rho}} & (1)\end{matrix}$

where M is the mass of the block, and ρ is the density of the materialcomprising the block. The occupancy ratio R_(o) can be defined accordingto the following expression:

$\begin{matrix}{R_{o} = \frac{V_{o}}{V_{e}}} & (2)\end{matrix}$

In various embodiments, the occupancy ratio may be less than about 0.15.In other embodiments, it may be less than about 0.10, and in yet otherembodiments it may be less than about 0.05.

The block may be formed into various sizes. For example, the W×D×Hmeasurements may be 2 ft×2 ft×3 ft, 1 ft×2 ft×3 ft, 1 ft×1 ft×2 ft, 2ft×2 ft×2 ft, or other dimensions scaled from these values. Reinforcingmembers 120 join to the vertical members 140 for the embodiment shown inFIG. 1A and increase the rigidity of the block structure. Holes 160 and105 disposed in the vertical members 140 and top 110 and bottom 190members reduce the amount of material required to form the block, andreduce its occupancy volume V_(o) without significantly reducing theblock's vertical compression strength. These holes additionally increasethe amount of volume available for liquid storage and facilitatemovement of liquid throughout the enclosed volume. In some embodiments,holes 150 may be used for strapping multiple blocks together asindicated in FIG. 2A. A synthetic cord or strap 220 may be threadedthrough holes 150 to secure an assembly of blocks.

The structure of the blocks provide substantial vertical strength, sothat a tank could be located under about 18 inches of topsoil, andsupport additional loading. The thickness of the vertical members 140and the top 110 and bottom 190 members can be dimensioned such that theblock supports a pre-selected amount of weight. For example, a blockmeasuring 2 ft×2 ft×3 ft is designed to support at least about 1,000pounds, or about 2 pounds per square inch, in some embodiments. Thisloading capability of the block permits safely the support of about 18inches of topsoil and one large person. In some embodiments, a block ofsimilar outer dimensions is designed to support at least about 4,000pounds.

In various embodiments, a modular block 100 has registration features104 and 108, which may be located on the outer edges of the top 110 andbottom 190 members. These features may be used to align and locktogether plural blocks. In the illustrated embodiment, a protrudingwedge 104, representing a male-type fastening mechanism, of one blockinserts into a V-groove receptacle 108, representing a female-typefastening mechanism, of an adjacent block. This fastening systemprevents vertical displacement of a block with respect to its adjoiningblocks.

Any number of blocks 100 may be assembled to form a liquid-storage tank200, as indicated in FIGS. 2A-2B. The blocks may be assembled using theregistration features 104 and 108, and then bound together usingsynthetic cord 220. The blocks may be formed into a two-dimensionalarray as shown in FIGS. 2A-2B, and they may be stacked to form athree-dimensional array (not shown). In various embodiments afterassembly, the skeleton of blocks is encased in a material 210 whichsubstantially prevents the outflow of water. This material may comprise,but not be limited to, a waterproofed fabric, a water-resistant fabric,a fiber-reinforced plastic, a rubber membrane, a vinyl sheet or aheat-shrinkable wrap. An advantageous feature of the blocks' smooth andsubstantially flat upper and lower surfaces is that they provide asubstantially uniform surface against the encasing fabric. This helpsprevent wear and puncturing of the fabric when the tanks are locatedunderground. Additionally, all outer edges of the block may be roundedand smoothed to further reduce the possibility of puncturing theencasing fabric.

In some embodiments, the covering 210 may include one or more entryports (331 in FIG. 3) and exit ports 239 for attaching a hose, tubing,pipe, vent or fluid-level guage. In other embodiments, the entry andexit ports may be added after encasing the blocks. For example, a holemay be formed in the covering 210, and a threaded hole may be formed inthe top 110 or bottom 190 members of the block. A hose fitting or pipefitting with a sealing gasket may then be screwed securely into theblock, where the fitting presses against the sealing gasket whichpresses against the underlying covering 210 and block 100.

As shown in FIGS. 1A-1B and 2A-2B the modular block provides aconvenient and potentially low-cost system for constructingliquid-storage tanks useful for rainwater recovery and reuse. Thematerials can be lightweight, and easily transported. An averagehomeowner could purchase the materials at a local supply store,transport them easily to the home, and assemble them without the need ofhiring professional, specialized tank-installation services.Additionally, safety considerations are reduced for the tank structureshown in FIGS. 2A-2B, since there is no large free-space volume intowhich a child or animal could fall.

The potential low profile of a tank formed from the blocks reduces thedepth of excavation necessary for subsurface installation of the tank.As an example of water storage capability, the tank depicted in FIGS.2A-2B, comprising 18 blocks measuring about 2 ft×2 ft×3 ft, would holdabout 1600 gallons of water, a volume equivalent to about sixstandard-size home-heating-oil tanks.

FIG. 3 is a schematic illustrating the incorporation of a liquid-storagetank into a rainwater-recovery system 330 for roof-top runoff. Invarious embodiments, the tank is connected to roof gutters 312 anddownspouts or tubing 315. In some embodiments, a multiple tanks may beused. The tanks collect and store rainwater runoff during rainfall, andmake it available for later non-potable uses. A pump 370 may beconnected to the tank 335 for future retrieval of the stored water, ordepending on the local grade of the land and location of the tanks, thewater may be extracted from the tank by a gravity-feed system. All of abuilding's roof area can be linked to the tank with aboveground orbelowground piping 315.

A buildings roof 302 can serve as a catchment area to collect rainwater.For a description of the use of a building roof as a catchment area andthe amount of water typically available, see A. W. Selders, SW-12,Agricultural Engineering, U.S. Department of Agriculture and WestVirginia University, Cooperative Extension Service, Oct. 17, 1971, theteachings of which are incorporated herein by reference. Water flowsfrom the roof 302, through a roof gutter 312, and through gutter conduitand piping system 315. The gutter conduit and piping system can comprise1-inch, 2-inch or 3-inch diameter PVC pipe with 45-degree and 90-degreeelbows, or flexible tubing. The collected water flows through afirst-flush system 320, and then to an entry port 331 of a storage tank335.

In various embodiments, the one or more tanks can be located in onecentral area or distributed around a building 300, and they may belocated underground or above ground. Because of their lightweightconstruction, a tank located above ground may be moved and stored insideduring winter months and placed in service outside during summer months.Because of their low profile, the tanks may be placed in about athree-foot-deep hole, easily dug by a homeowner, and covered with about18 inches of soil for gardening. Multiple tanks may be linked togethereasily with tubing or piping 315 to increase storage capacity for theirrigation of larger lawns or gardens, or a tank of virtually any sizemay be assembled due to the modularity of the blocks.

Most any type of hose or piping can be used to link multiple storagetanks together. Hose connections can be made with 1-inch-diameter orlarger hose, tubing or piping. Various length hoses, tubes or pipes andhose nipples, clamps, pipe junctions, couplers and elbows and bulkheadfittings may be used. For example, an entire water-recovery system 330may be interconnected with inexpensive and readily-available PVC tubing.In some embodiments, any of a variety of valves can be used to providemanual control of liquid flow within a multiple tank system.

In embodiments to provide for heavy and excessive rainfall, the one ormore storage tanks 335 may be connected to a dry well 355. Any excesswater is directed to the dry well, which permits infiltration of thewater into the ground and assists in recharging the groundwater supply.Any additional overflow from the dry well can be directed away from thehouse or building structure 300. In various embodiments, the dry wellconstruction requires excavation of about 85 cubic feet for a 600 gallondry well and 2000 square foot roof area. Examples of dry well systemsare described in U.S. Pat. Nos. 6,095,718 and 5,848,856 both to Bohnhoffand U.S. Pat. No. 4,689,145 to Mathews et al., the teachings of whichare incorporated herein by reference.

The pumping system 370 can be used to convey water from the storage tank335 to various non-potable applications 390 such as, but not limited to,irrigation of lawn, shrubs, trees and garden, and washing of cars,building, driveways and walkways, and supplying ornamental fountains.The pump may be located within the tank 335 or located external to thetank system. In some embodiments, the pump may be located within thebasement of a building 300 for convenient servicing. The pump may alsobe located above ground or below ground. Various adaptor valves andfittings, and pipes, tubing and hoses 315 may be used to connect thepump to the tank 335.

The water-recovery system 330 can be equipped to deal with many possibleforms of contamination from the rooftop. A first level of protection canbe in the form of a removable, cleanable screen, disposed over thegutter 315 to catch leaves and large solids. A second level ofprotection is a flow diverter 320 which minimizes potential chemicalcontamination by diverting a first-flush runoff water away from therecovery system 330. A third level of protection is in the storage tanksthemselves. They serve as a settling basin for any suspended solids thatenter the tanks. Finally, the dry well can include a maintenance portenabling periodic cleanout.

An embodiment of the first-flush system 320 is depicted in greaterdetail in FIG. 4. Water entering an inlet from the catchment area flowsinto a primary tank 321, and flows into an empty secondary tank 329through an opening 324 located at the bottom of the primary tank. Aswater collects in the secondary tank 329, float 328 attached to arm 327mounted securely on hinging assembly 326 rises. As more first-flushwater enters the lower tank, the arm rises and the attached stopper 325plugs the opening 324. Once the hole 324 is plugged, subsequent waterwill flow out the exit port and to the cistern or storage tank system.In this manner, the contaminated first flush of water is diverted awayfrom the water-recovery system 330.

In various embodiments, the amount of water collected in the secondarytank 329 can be adjusted according to the size of the catchment area.This can be done coarsely by selecting a size of the secondary tank 329,and finely by adjusting the height of the stopper 325 with respect tothe float 328. In some embodiments, the first-flush system can beconfigured to collect the first 1 millimeter of water that falls on thecatchment area.

The secondary tank 329 can be adapted to provide evaporative removal ofthe collected water, e.g. holes may be located along its upper exteriorsurface, or it may extend and open outwards in the form of anevaporative pan. First-flush water with contaminants can collect in thepan during a storm, and the water may evaporate between storms leaving asolid residue. The solid residue may be easily cleaned from the pan.

In some embodiments, the first-flush system can be automated withelectronic valves. In such an embodiment, a rainfall sensor can detectthe start of a rain storm and actuate an electronic valve which providesan opening for fluid flow into the secondary tank 329. A float withinthe tank could then trigger the closing of the electronic valve.

Introducing the catchment runoff water to the water-recovery system 330in this manner helps prevent the introduction of pollutants, such as oiland other contaminants which may collect on catchment surfaces duringdry periods, into storm drains, surface and ground waters. Furtherexamples of systems for removing pollutants from stormwater aredescribed in U.S. Pat. No. 6,241,881 to Pezzaniti and U.S. Pat. No.6,086,756 to Roy, the teachings of which are incorporated herein byreference.

Although the embodiments described above pertain substantially to aparticular modular block style and a particular use in a roof-top,rainwater catchment application, other embodiments of block styles andapplications exist.

Examples of other modular block styles are illustrated in FIGS. 5A-5Band FIGS. 6A-6B. The modular block shown in FIGS. 5A-5B is similar tothat shown in FIGS. 1A-1B except for the vertical members 140. For theblock shown in FIGS. 5A-5B, the vertical member 540 comprises acylindrical tube. Holes 550 and 560 are disposed in the tube for similarpurposes as described in connection with FIGS. 1A-1B.

In an additional variation to the block style, slight convex or concaveshapes may be incorporated into the upper 110 and lower 190 surfaces ofthe block 100. A convex shape may provide added compressive strength,and still provide a substantially smooth outer surface. Also, convex orconcave upper and lower surfaces may reduce any tendency for lateralmotion of the blocks when located underground.

Two embodiments depicting interlocking systems for the modular blocksare shown in FIGS. 6A-6B. A dovetail-type interlocking system isdepicted in FIG. 6A. For this embodiment, a flared bar 604 having acentral slot 603 extends along one or more edges of the upper blockelement 610A. (Although not shown, the same features can be included onthe blocks lower element.) Receptacles 608 are located on the opposingsides of the element 610A. When the blocks are pressed together, theslot 603 allows compression of the outer edges of the flared bar 604, sothat the bar snaps into the receptacle 608 in the adjacent block.

FIG. 6B depicts an embodiment for interlocking the blocks wherein one ormore fasteners 680 are pressed into receptacles on the block's upper andlower surfaces. The fastener 680 is dumbbell shaped having two enlargedends 682 and a linking bar 681. The receptacles can be readily formed inthe upper and lower block surfaces during block manufacture and compriseholes 105 and channels 675. After the blocks are aligned, the fasteneris pressed into the receptacles such that the enlarged ends 682 recessinto a portion of the holes 105 and the linking bar 681 recesses intothe channels 675. The fasteners may be fabricated from syntheticmaterial, e.g. nylon, vinyl, polyvinylchloride, polycarbonate, etc. Forthe embodiment shown in FIG. 6B, it may not be necessary to usesynthetic cord or straps 220 to bind the blocks as shown in FIG. 2A.

In other embodiments, synthetic or metallic pins or pegs may be used toattach the blocks. For example, holes may be formed in the outer edgesof the block's upper 110 and lower 190 elements. One or more pins may bedriven into the holes such that about one-half of a pin's length remainsoutside the block. An adjacent block with matching holes may then bedriven onto the protruding pins.

The modular blocks 100 and water-recovery system 330 can be used inother embodiments. For example, the system may be used to collect runoffwater from other water impervious surfaces such as driveways, walkways,decks and patios. Larger systems may be employed for parking lots. Thetanks may also be used for septic systems in some locations whereconforming to local code.

The water recaptured by this system will help relieve demand onmunicipal water systems in urban and sub-urban areas, particularlyduring the summer months. This can help sustain public drinking watersupplies. Any water infiltrated by the dry well 355 will promoterecharge of groundwater supplies and enhance aquifer storage. Thewater-recovery system provides useful storage and reduces loss of stormwater runoff.

EXAMPLES Example 1

As an example of the rainwater-handling capability of the water recoverysystem 330 illustrated in FIG. 3, a system servicing a 2000 square-footroof area is considered. The system of this example has only one800-gallon storage tank 335 and one 600-gallon dry well 355. A storagetank for holding about 800-gallons of water can be constructed from ninemodular blocks 100 measuring about 2 ft×2 ft×3 ft. Construction for a600-gallon dry well requires excavation of about 85 ft³. The totalvolume of the system, about 1400 gallons of water in this example, canbe collected and recovered for subsequent use. The actual amount ofrecovered water may be greater than this amount depending on the rate ofrainfall and rate of infiltration of water from the drywell 355. Forthis example, a rainfall of about 1.12 inches falling on the 2000-ft²roof area would substantially fill the system, assuming no infiltrationof water into the ground from the drywell.

All literature and similar material cited in this application,including, but not limited to, patents, patent applications, articles,books, treatises, and web pages, regardless of the format of suchliterature and similar materials, are expressly incorporated byreference in their entirety. In the event that one or more of theincorporated literature and similar materials differs from orcontradicts this application, including but not limited to definedterms, term usage, described techniques, or the like, this applicationcontrols.

The section headings used herein are for organizational purposes onlyand are not to be construed as limiting the subject matter described inany way.

While the present teachings have been described in conjunction withvarious embodiments and examples, it is not intended that the presentteachings be limited to such embodiments or examples. On the contrary,the present teachings encompass various alternatives, modifications, andequivalents, as will be appreciated by those of skill in the art.

The claims should not be read as limited to the described order orelements unless stated to that effect. It should be understood thatvarious changes in form and detail may be made by one of ordinary skillin the art without departing from the spirit and scope of the appendedclaims. All embodiments that come within the spirit and scope of thefollowing claims and equivalents thereto are claimed.

1. A liquid-storage tank comprising: at least one block, the blockhaving: a substantially rectangular lower element perforated with atleast one hole; a substantially rectangular upper element perforatedwith at least one hole, the lower element and the upper elementsubstantially parallel to each other; and at least one vertical supportmember connecting the upper element and the lower element, the supporthaving at least one perforation; a covering material enclosing the atleast one block to form a liquid-storage volume; at least one liquidinlet into the storage volume; and at least one liquid outlet from thestorage volume.
 2. The apparatus as claimed in claim 1 wherein the atleast one block can support a vertical loading of at least about twopounds per square inch and wherein the occupancy ratio of the at leastone block is less than about 0.10
 3. The apparatus as claimed in claim 1wherein the at least one block can support a vertical loading of atleast about four pounds per square inch and wherein the occupancy ratioof the at least one block is less than about 0.10
 4. The apparatus asclaimed in claim 1, the at least one block further including: at leastone integrated female-type fastening mechanism located on each of atleast two sides of each block; and at least one integrated male-typefastening mechanism located on each of at least two sides of each block;wherein the female-type and male-type fastening mechanisms enableregistered assembly of plural, substantially similar, rectangular-shapedblocks.
 5. The apparatus as claimed in claim 1 wherein the verticalsupport of the at least one block comprises at least one wall-likestructure having plural perforations, the wall like structure beinglocated and attached substantially along a diagonal of the upper andlower elements; and further includes at least one reinforcing bracecomprising a planar member, oriented substantially parallel to the upperand lower elements and attached to one or more vertical support members.6. The apparatus as claimed in claim 1 further including: synthetic cordthreaded through at least one perforation in at least one verticalsupport of each block located at the periphery of an assembled multipleblock structure, the synthetic cord providing structural reinforcementof the assembled block structure.
 7. The apparatus as claimed in claim 1wherein the at least one block is fabricated from a synthetic materialusing a process selected from the following group: extrusion, injectionmolding, rotational molding, or casting.
 8. The apparatus as claimed inclaim 1 wherein the material used to form the at least one block isselected from the following group: nylon, vinyl, polyvinylchloride,polycarbonate, acrylic, polyethylene, polyurethane, or polystyrene. 9.The apparatus as claimed in claim 1 wherein the upper element and thelower element are substantially flat.
 10. The apparatus as claimed inclaim 1 wherein at least a portion of the upper element and at least aportion of the lower element incorporate a shape selected from thefollowing group: convex and concave.
 11. The apparatus as claimed inclaim 1 further including: at least one dry well connected to theliquid-storage tank.
 12. The apparatus as claimed in claim 1 furthercomprising: a pump connected to the liquid-storage tank; and at leastone roof-water collection system connected to the liquid-storage. 13.The apparatus as claimed in claim 12 further comprising at least onefilter disposed between the at least one roof-water collection systemand liquid-storage tank connected thereto.
 14. The apparatus as claimedin claim 12 further comprising at least one roof washer disposed betweenthe at least one roof-water collection system and liquid-storage tankconnected thereto, the at least one roof washer includes a flow diverterthat diverts a first flush of water away from the liquid-storage tankconnected thereto and permits water in excess of said first flush ofwater to flow to the liquid-storage tank connected thereto.
 15. Amodular block adapted for constructing a liquid-storage tank comprising:a substantially rectangular lower element perforated with plural holes;a substantially rectangular upper element perforated with holes, thelower element and the upper element substantially parallel to eachother; at least one vertical support member connecting the upper elementand the lower element, the support having plural perforations; at leastone receptacle for receiving an interlocking fastener; wherein the blockis adapted to support a vertical loading of greater than about twopounds per square inch, has an occupancy ratio of less than about 0.10,has a substantially smooth outer surface, is adapted to be registeredand assembled with plural similar blocks, and is adapted to permitmovement of liquid to and from all regions within an assembly of pluralsimilar blocks.
 16. The apparatus as claimed in claim 15 wherein thevertical support member is substantially cylindrical in shape.
 17. Theapparatus as claimed in claim 15 wherein the vertical support of the atleast one block comprises at least one wall-like structure having pluralperforations, the wall like structure being located and attachedsubstantially along a diagonal of the upper and lower elements; andfurther includes at least one reinforcing brace comprising a planarmember, oriented substantially parallel to the upper and lower elementsand attached to one or more vertical support members.
 18. The apparatusas claimed in claim 15 wherein the material used to form the at leastone block is selected from the following group: nylon, vinyl,polyvinylchloride, polycarbonate, acrylic, polyethylene, polyurethane,or polystyrene.
 19. The apparatus as claimed in claim 15 wherein theupper element and the lower element are substantially flat.
 20. Theapparatus as claimed in claim 15 wherein the at least one receptacle islocated on the outer surface of upper element or the lower element, andis adapted for recessing of the interlocking fastener into the upper orlower element.
 21. A method for storing non-potable liquid comprising:forming a tank structure by registering and assembling plural similarmodular blocks, each block having: a substantially rectangular lowerelement perforated with plural holes; a substantially rectangular upperelement perforated with holes, the lower element and the upper elementsubstantially parallel to each other; and at least one vertical supportmember connecting the upper element and the lower element, the supporthaving plural perforations; covering the tank structure with asubstantially water impermeable material; and providing at least oneport for conveying liquid into or out of the tank.
 22. The method ofclaim 21 further comprising: burying the tank structure underground. 23.The method of claim 21 further comprising: connecting a pump to the atleast one port.
 24. The method of claim 21 further comprising: providingstructural reinforcement of the assembled block structure by threadingat least one synthetic cord through at least one perforation in at leastone vertical support of each block located at the periphery of anassembled multiple block structure and binding the assembled blocks. 25.The method of claim 21 further comprising: collecting non-potable waterin the formed tank.